Archive for February, 2013

Last summer UNESCO’s World Heritage Committee threatened to downgrade its listing of the Great Barrier Reef from World Heritage Area to Heritage Site in Danger. Downgrading the listing could repel tourists, and ought to be a blow to national pride.

The Great Barrier Reef, managed well since 1994, remains threatened by pollution, warming seas and now coal and natural gas facilities at its southern end (bayrun.com.au)

The GBR has suffered stress from the usual suspects for decades – overfishing, mining, Crown-of-Thorns starfish plagues, run-off from adjacent mainland coastal farms. Now add to those the coral bleaching and intense cyclones of recent years associated with climate change, as well as the looming devastating impact of ocean acidification. Not surprisingly, half the coral cover has been lost or damaged since the 1980s.

Coral bleaching has killed and damaged corals on the GBR just as it has on reefs around the world (scienceonline.org)

The World Heritage Committee based its threat on the recent developments at Gladstone and nearby Curtis Island, at the southern end of the reef. Gladstone has become the largest center for coal export in Australia – there are huge seams of coal running north-south in the eastern part the country adjacent to the reef. The coal is sent where you would expect, to Japan, China, South Korea and India. Now the port of Gladstone is being dredged even deeper to handle ever more and larger ships.

The eastern part of Australia is rich in coal resources (Haliburton.com).

That’s part of UNESCO’s concern.

The other part involves coal seam gas, gas that is or can be extracted during the coal mining process. Curtis Island, lying close to Gladstone, is actually part of the GBR World Heritage Area. However, it is now under extraordinary development to liquefy the coal seam gas to liquid natural gas (LNG), and send it off in refrigerated tankers to consuming nations where it will rendered back into natural gas. The liquid takes up 1/600th the volume of the gas, so the advantage of shipping it as liquid is obvious.

The World Heritage Committee report (p20-22) calls for these developments to cease and for a review of their impact. Since no actual sanctions by UNESCO are possible, beyond downgrading of the status of the Reef, what kind of response can we expect?

The Queensland Government has now submitted a defensive response, promising an independent review of the the Port of Gladstone, and commenting on existing water quality improvement programs, research initiatives, the GBR zoning plan, the Coral Sea reserve, and the recently implemented national carbon tax. The number of gas ports under development will be limited, but they will still be in the World Heritage Area.

However, as the Premier of Queensland said early on, ‘We are in the coal business’. That hasn’t changed.

So there will be no reconsideration, no precautionary plan, no delay in port or LNG development. The long-term threat to the reef is dismissed.

Is this anyway to treat a World Heritage Area? Liquid Natural Gas facilities under development on Curtis Island (Greenpeace.org)

We shouldn’t be surprised. Extract and sell is the mantra of resource exploitation in Canada, the US, Africa, South America, Asia – and Australia. The exported coal and LNG from Gladstone and Curtis Island will no doubt support the Queensland economy, providing jobs and infrastructure. Unfortunately, given the other stresses that already exist, there isn’t any reason to think that a severely damaged GBR will be able to recover.

The tension between extracting resources and conserving natural ecosystems is familiar to us everywhere. You would think one place where conservation trumps extraction would be The Great Barrier Reef. Apparently not.

Will anyone listen to the outcry in defense of the Great Barrier Reef? If you would like to add your voice, visit: ‘Save the Reef’ It could only help.

We’re losing or have already lost the apex predators from most of our ecosystems. This has been going on for a long time – remember saber toothed tigers? – so it’s obviously not news that we are a particularly difficult species to co-exist with.

Over the past few decades global capture fisheries have added most of the large fish species of any commercial value to the list of missing apex predators. Among those that are still with us, an unexpected response has occurred.

In a comparison of 37 commercially fished stocks, the majority matured earlier and at a smaller size. The effect is clearest in heavily fished populations.

The size of first spawners of Arctic cod has declined, as it has in many other heavily fished species (nature.org).

Is this a genetic change, an evolutionary shift towards smaller size-at-age due to the selective harvesting of the oldest, largest and fast-growing individuals? If it is, it is a dramatic change, and will be difficult to reverse.

It could as well be a response to climate change, with physiological declines in growth rates occurring due to increasing sea temperatures and decreasing oxygen in warmer oceans.

At the same time, we wonder why fish that we have overfished don’t recover when we stop harvesting them. With their huge reproductive potential, fish surely should be resilient, and recover quickly. Famously, though, the cod of the northwest Atlantic have not recovered from their collapse.

The famous graph of exploitation of cod in the northwest Atlantic, leading up the moratorium in Canada in 1992. (Wikipedia.org)

Why not? What stops or delays recovery? And what have we actually learned about the impact of the damage we have done to marine ecosystems?

In fact we have learned quite a lot. We have learned that the responses of an ecosystem to the loss of apex predators are likely to be complex and convoluted, and often unpredictable. Shifts occur within the community of species, involving changes in mortality rates, growth rates, competitive interactions, and prey-predator relationships. (Two fine reviews worth reading were published in Science: Estes et al, July 15, 2011; and Garcia et al, March 2, 2012)

Pandalus borealis, the northern shrimp, became abundant after the collapse of cod, and is in part responsible for the lack of cod recovery. It is also the sweetest shrimp you would ever want to eat. (biology.com)

We have also learned that sufficiently perturbed ecosystems break abruptly into alternative stable states that are usually of lower trophic status and of far less commercial value. Coral reefs have become algal covered rubble. Jellyfish have replaced fish as top consumers.

We have learned that trophic degradation is an inevitable outcome of eliminating or radically reducing apex predators.

And we have learned that there are limits to resilience.

Iconic cod are showing signs of recovery in the northwest Atlantic – not enough to lift the moratorium, but enough to suggest hope lives (ctv.news0

Out of these fisheries disasters has comes some decent advice. For instance, fishing pressure should be spread over more species and sizes, probably netting more fish, but reducing the risk of wiping out a species or restructuring the community. Biomass drops but not biodiversity,
a more ecosystem-based approach.

But also we are aware that the only truly reasonable response is to try to restore the apex predators. If we don’t, biodiversity will decline, trophic degradation will continue, ecosystem phase shifts will occur, and the current global mass extinction will just continue. The world becomes ever more diminished.

Cod captured by trawler in 1949 were often huge. Nevermore. (heritage.nf.ca)

Does it help to understand the reasons for a catastrophe, if there seems to be little chance of preventing or recovering from it?

The answer must be yes. If recovery from the catastrophe is even remotely possible, we can encourage it. And we can use our knowledge to mitigate the impact of other catastrophes-in-waiting.